Clutch advice

[Mike Biddle]

The RST came with a 7.25 superclutch with organic plates and concentric slave cylinder.

 

It would appear that this device is somewhat inadequate when it comes to reining in all those horses, so need to sort out a different one ready for the summer.

 

Have pretty much decided on a 7.25 cerametallic, but would apreciate views on manufacturers.

 

Also decided that a better quality slave cylinder is required.

 

So which breed should i buy? i saw the Tilton during Autosport and it looked like very high quality stuff albeit more expensive (not an issue), otherwise AP?

 

Thanks, Mike.

 

 

 

[F355GTS]

Mike

 

i'm runnign a 7 1/4 twin plate Superclutch wth metal (rally spec) plates, it's tough and has definitely stood some serious abuse whilst retaining a large element of driveability at low speeds, manouvering. I previously had hte Organic plates an cooked them!

 

I recently tried an AP twin plate cerammetallic and it was somewhat agressive compared to the above

 

Mark

[ECR]

My experience is as follows (generalising):

Sintered: Like a light switch either on or off - race use only

Organic: relatively gentle takeup but does not last with high power

Cerametallic: Lasts well and is the best compromise for high power road and track. This is what I am running. The plate (AP) was re lined when finally worn at a very sensible price by Questmead

 

Edited by - ECR on 26 Mar 2007 10:07:47

[Alex Wong1697456877]

My humble 240BHP Vx set fire (literally) to a set of QM organic plates.

 

They were not very durable at all. So far so good with the rally plates but with your level of power, I'd maybe talk to QM or Tilton and see what they suggest.

 

Edited by - Alex Wong on 26 Mar 2007 10:23:03

[Mike Biddle]

Mark, thanks for the info, i did run a 5.5 sitered clutch with the old VX motor and had to mess with the pedal to master cylinder ratio by weldin in a pivot and two levers in order to make it in any way usable, but that of course was on a 5.5 unit and a 7.25 with softer springs could well be very different, and in any case this time round a smaller master cylinder has been fitted to change the ratio, and that has made a very big difference in pedal effort, travel, and "feel" I'll bear it in mind.

 

Alex, I have talked to AP and Tilton, they both suggest a cerametallic unit with the appropriate cover springs to handle the torque, and thats what makes for a heavy pedal. Fortunately I don't have an overdose of torque, so it should be ok given the smaller master cylinder. Probably not too much more torque than your VX actually.

 

When you say "rally plates" are they cerametallic or sintered?

 

 

[Alex Wong1697456877]

I don't know - the Quartermaster catalogue just refers to them as Rally plates. I believe Marius found these wore out pretty quickly too but mine have proved to be a great improvement over the organic plates. The clutch is a Quartermaster 7.25 twin plate V-drive. I'm guessing they are cerametallic. In use, they are only slightly more aggressive than the organic plates.

 

If I was starting from new, I think I'd go for a Tilton one. Can't justify that any further than gut feeling though.

 

Edited by - Alex Wong on 26 Mar 2007 12:15:12

[Mike Biddle]

Thanks Alex, I can find out from that info.

 

Incidentaly the car will be living at our Halesowen facility for the summer, maybe we could go for a blat sometime when I'm over there?

 

Mike.

[Alex Wong1697456877]

Good idea - let me know when you're around.

[Peter Carmichael]

Mike,

 

I've designed a slave cylinder that has an appropriate ratio. I can dig out the drawings if you like. My 1st prototype has been running in my car for ... let me see now... seven years. 😬

[Mike Biddle]

Thanks Peter, I would really apreciate that. I assume your slave works with the standard master cylinder?

 

Getting it made is not a problem.